Fuxploider for File Upload Vulnerability Testing

Fuxploider is an open-source Python tool designed to automate the assessment of file upload vulnerabilities in web applications. It examines upload functionality, identifies accepted file types, and tests techniques that may bypass server-side restrictions during an authorized penetration test.

File upload flaws can expose a web server to serious risks if an application accepts dangerous files or stores them in locations where they can execute. Fuxploider helps security testers investigate these weaknesses and understand how an application’s upload validation behaves.

Fuxploider Features for File Upload Testing

Fuxploider automates several stages of file upload security testing, reducing the need to check every file type and validation rule manually.

File type detection: Tests how an upload form handles different file extensions and formats.
Validation bypass checks: Examines whether configured upload restrictions can be circumvented.
Upload technique testing: Evaluates methods that may allow a file to pass through application filters.
Python-based workflow: Runs from the command line and supports scripting-friendly testing environments.
Docker support: Provides an alternative way to build and run the tool in a container.

Results depend on the upload form, authentication requirements, server configuration, and response patterns. An accepted file does not automatically mean the application is vulnerable to code execution.

Install Fuxploider on Linux

Fuxploider requires Python 3.6 or later according to the original installation instructions. Start by cloning the project’s repository and installing its dependencies.

git clone https://github.com/almandin/fuxploider.git
cd fuxploider
python3 -m pip install -r requirements.txt

Using python3 -m pip can help resolve cases where the system’s pip3 command points to a different Python installation. If dependency installation fails, check the Python version and the project’s current compatibility requirements.

Build the Docker Image

If you prefer a container-based setup, build the image from the cloned repository directory. Docker must already be installed and running.

docker build -t almandin/fuxploider .

This command creates a local image named almandin/fuxploider. Follow the repository’s instructions for running the image and supplying the necessary arguments.

Fuxploider Command-Line Usage

Check the available options before starting a test. The help output explains the flags supported by your installed version.

python3 fuxploider.py -h

For an authorized test environment, the following example shows the basic command structure from the original usage instructions. Replace the example address with an upload endpoint you own or have permission to assess.

python3 fuxploider.py --url https://upload.example.test --not-regex "wrong file type"

The --url option specifies the target upload endpoint, while --not-regex supplies a response pattern that can help the tool distinguish an upload rejection from other responses. Match the expression to the application’s actual error message. The original example contains an extra closing bracket after the expression, which should be omitted.

Review Upload Findings and Reduce Risk

Use Fuxploider only against systems you own or are explicitly authorized to test. Start with a staging environment and harmless test files wherever possible. Avoid uploading web shells or other executable payloads to production systems without a clearly approved test plan.

After testing, verify findings manually and review the server’s response, stored file location, and execution behavior. Developers can reduce upload risks by allowlisting required file types, validating file contents on the server, generating safe filenames, limiting upload permissions, and storing uploads outside executable web directories.

For additional web reconnaissance, see WhatWeb, the next-generation web scanner. The official Fuxploider GitHub repository provides the source code and project-specific instructions.